Sound-box diaphragm



UNITED STATES PATENT OFFICE.

HERBERT L'. TIFF'I', OF WILLIMANTIC, CONNEOTICI TT.

SOUND-BOX DIAPHRAGM.

No Drawing.

T 0 all 10 710m it may concern Be it known that I, HERBERT L. Trrr'r, acitizen of the United States, residing at Willimantic, in the county ofWindham and State of Connecticut, have invented certain new and usefulImprovements in a SounchBoX Diaphragm; and I do hereby declare thefollowing to be a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains tomake and use the same.

The object of the invention is to provide a diaphragm for use inconnection with sound boxes or reproducers of phonographs, graphophonesand like instruments and suit able both for recording and reproducingwhereby the disagreeable false tones ordinarily emitted, together withscreeching metallic dissonant sounds and the like are eliminated orsubdued to such an extent to be inaudible or negligible and wherebyclear, relatively loud and resonant and at the same time musical tonesare produced; and with this object in View, the invention con sists in adiaphragm produced substantially as follows:

The base or body of the diaphragm is of fibrous material, preferablyEgyptian hard fibre of a thickness or gage of approximatelyone-sixtyfourth of an inch. This base or body is treated by saturationor impregnation to a solution of gutta percha in carbon lL-isulphide asfor example in the following proportions Carbon bisulphide, 20 fluidounces.

(rutta percha (pure), 1% ounces.

A i'ter the base has been thoroughly saturated in the above solution andit has been permitted to dry, it is treated with a preterably heavy coat0t liquid gold bronze and then permitted to dry as at normal atmospherictemperature.

Specification of Letters Patent.

Application filed March 31, 1921..

Patented July 18, 1922.

Serial No. 457,506.

Before applying the finishing coat of liquid bronze, however, I havefound it de sirable in most instances to stiiien the disk by theapplication to the surface thereof of liquid glue, which also has theeffect oi furnishing a hard surface for theapplication of the metallicor final coating.

Having thus described the invention, What I claim is 1. A. diaphragm torthe purpose indicated consisting of a fibrous base saturated With asolution of gutta percha and having an exterior metallic coating.

2. A diaphragm for the purpose indicated having a fibrous base saturatedwith a solution in carbon bisulphide of gutta percha and treated with anexterior coating of gold bronze.

A diaphragm for the purpose indicated consisting of a base of Egyptianhard fibre saturated with a solution in carbon bisul phide oi guttapercha and treated. With a coating of gold bronze.

i. A diaphragm for the purpose named consisting of a fibre basesaturated With a solution of gutta percha and having a surfaceapplication of glue surmounted by a me tallic coating applied in liquidstate.

A diaphragm tor the purpose indicated consisting of a base impregnatedWith gutta percha and having an exterior finishing coating.

6. A. diaphragm tor the purpose indicated consisting of a baseimpregnated With gutta percha and having an application of a stiffeningmedium thereon.

in testimony whereof I aflix my signature in presence of two Witnesses.

HERBERT L. TIFF Witnesses .ho'rrm M. LEE,

ELMER M. YOUNG.

